Marri Plant Care

Marri (Arillastrum gummiferum) belongs to the Myrtaceae family within the Arillastrum genus. Marri is native to southern New Caledonia. Marri is also known as Red Gum.

Marri displays a tall, upright tree growth habit, reaching up to 15 ft tall with a spread of approximately 8 ft. Marri produces small white flowers in clusters.

Leaf size: approximately 4 inches.

Water a young or newly planted Marri every 7–14 days, soaking the whole root zone, until it is established — usually one to two growing seasons. Established trees mainly need water during long dry spells. In a container, water whenever the top few centimetres of soil are dry.

Marri thrives in full sun to partial shade.

Arillastrum gummiferum tolerates temperatures of 60–85°F. Marri prefers humidity levels of 40–70%.

Well-draining loamy soil with added organic matter for moisture retention. Good drainage is essential for Marri to prevent waterlogging, which leads to root rot and fungal issues.

Feed Marri every 6 months during the growing season with a balanced, slow-release fertilizer at the rate on the label. Established trees in good soil often need little extra feeding, so let weak growth or pale foliage guide you.

Stop feeding by late summer so new growth can harden before winter.

The PlantoScan app can remind you when to water and when to fertilize each plant.

Choose a spot with full sun to partial shade and well-draining loamy soil with added organic matter for moisture retention. Avoid low spots where water collects after rain.

Marri is suited to USDA Zone 10b – 12b.

Plant container-grown or balled-and-burlapped trees in spring or early autumn, setting the root flare at soil level, and water well after planting.

Marri can spread to about 8 ft (2.4 m) and reach about 15 ft (5 m) tall. Space plants about 8 ft (2.4 m) apart so mature crowns don't crowd each other, and plant at least half that distance from buildings, fences and paths.

Planning a row or hedge? Try the tree spacing calculator.

Prune Marri while it is dormant in late winter: first remove dead, damaged and crossing branches, then thin lightly for shape.

If it flowers in spring, prune right after flowering instead so you don't remove next year's buds. Never take off more than about a quarter of the tree in one year.

Marri is frost-tender (hardy to USDA zone 10). In colder areas grow it in a container and move it to a bright, frost-free place before the first frost.

Marri can be propagated through seeds, softwood cuttings.

See all plants toxic to cats and plants toxic to dogs.

Marri is susceptible to aphids, scale insects, spider mites. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.

Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.

Marri grows outdoors in USDA Zone 10b – 12b. It survives winters down to planting zone 10b. Marri is native to southern New Caledonia. In cooler regions, grow Marri as a houseplant or bring it indoors before the first frost.